EP1764327A1 - Roll winding device - Google Patents

Abstract

A paper mill has a paper web winding assembly with a roller that takes up the paper web. The winding assembly has a natural frequency arising from its dynamic running characteristics and a frequency modification assembly (100). The frequency modification system switches the frequency between two or more values and is continually variable and acts by altering the roller bearing stiffness.

Description

The invention relates to a reel winding device with at least one roller to which a winding roll is applied during winding.

The invention will be described below with reference to a roll winding device which winds a paper web to form a winding roll. However, it is not limited to this application.

A paper web is produced in a relatively large width of currently up to 12 m and virtually endless. In order to be usable for a later consumer, the paper web must be divided into narrower webs. These narrower webs must then be wound into rolls. For this purpose, a roll winding device is used.

In some reel winders, which are also referred to as "slitter" occur in operation problems due to strong vibrations, the result of poor windings, heavy use of Machine and the foundations, reduction in production speed or roller swings to roll ejection are. In reel winders sought for imbalances in rollers or reels, after vibrations in the drive and control system, etc. Changes, which are usually associated with much effort, have not been able to completely resolve the difficulties.

Occurring vibrations with concomitant out of roundness of the winding roll may be associated with the processing of certain types of paper. For example, the friction behavior or the paper thickness represent relevant quantities.

It is believed that contact vibration between the winding roll and the roll or rollers is causative of the out-of-roundness of the winding roll, the roll or rolls and the winding roll or parts thereof, e.g. the outer shell of a limited number of paper layers, swing against each other. This can lead to a non-uniform structure of the winding roll (density, stiffness, thickness variation, air pockets, shifting paper layers), which in turn can increase the contact vibrations.

At the end of the winding process, the bobbins are decelerated to a standstill. If the rotational frequency of the winding roll passes through the natural frequency of the oscillation of the entire system, then a roll swings can occur. The winding roll vibrates, which can lead to a role ejection.

Vibrations occurring during the winding process are classified into two problem areas, namely roll hum and roll swings.

The roller humming is a contact vibration between the winding roller and the roller or the rollers, wherein when using several rollers, on which the winding roller is applied, the rollers can oscillate against each other. Roller rumbling may occur when a harmonic of the rotational frequency of the winding roll or winding rolls (when several winding rolls are wound simultaneously) is in the range of the natural frequency of the contact vibration.

Due to the roll humming it can lead to a non-uniform structure of the paper in the winding roll, which in turn can increase the contact vibrations.

The invention has for its object to avoid critical conditions when winding.

This object is achieved in a roll winding device of the type mentioned above in that a system natural frequency changing means is provided, with which a system natural frequency of a system formed from the roll winding device and winding roll is changeable.

Starting point of the invention is that the contact vibration occurs at a harmonic of the rotational frequency of the winding roll in conjunction with a system natural frequency. To avoid the contact vibration therefore a change device is provided, with which the system own frequency can be selectively changed. The system frequency is suitably changed in operation in such a way that the amplitude of the contact vibration occurring in the approach is reduced in the associated harmonic, so that as a result of no further uneven Wi-ckelaufbau can train more. If, due to the changed system natural frequency, a contact oscillation occurs at another harmonic, the system natural frequency can be shifted again.

In a preferred embodiment, it is provided that the system natural frequency can be switched between at least two values. This is a particularly simple solution. Two discrete values of the system eigenfrequency can be realized with little effort. If a vibration results in a system natural frequency, you can switch the reel winder to another system's own frequency and there continue to wind until, for example, there is a critical state. In this case, it is switched back again.

In an alternative embodiment it can be provided that the system natural frequency is continuously variable. In this case one can avoid a critical condition continuously.

Preferably, the system own frequency is variable via a change in the roller or the roller bearing. The roller or roller bearings are elements of the reel winder which do not change during operation without external intervention. They are therefore available in defined states, so that this state can be changed from the outside.

Preferably, the winding roll is mounted and the system natural frequency is variable via a change in the bobbin storage. The winding roll is part of the oscillating system. While in a Doppeltragwalzenwickler, so a roll winding device in which the winding roller rests on two support rollers, a bobbin storage is usually not present, it is in a back-up roller or contact roller given. About the bobbin storage can now influence the winding roll and thus take on a component of the oscillating system.

Preferably, the rigidity of the roller bearing is variable. This is a relatively simple measure to change the system natural frequency of the reel winder with winding roll.

In a simple way, this can be realized in that the roller is either rigid or soft storable. By simply changing the storage, the system natural frequency can be changed.

This can be realized for example by the fact that the roller is mounted with a bearing which can be coupled either to a foundation or a stoma or stored on a suspension spring. The term "suspension spring" is to be understood here functionally. The spring can therefore also be formed by a gas spring or a hydraulic spring.

Preferably, the soft bearing is combined with a damper. A damper, such as a friction damper, effectively removes energy from any possible vibration.

Preferably, the damper on a variable damping. You can then adjust the system's own frequency also via the change in damping.

Preferably, the damper is designed as a locking device. This can be realized for example by the fact that the damper gets such a high coefficient of friction that it no longer allows movement.

In an alternative embodiment, the damper is designed as a hydraulic damper. In a hydraulic damper, the oscillation energy is converted into heat by flowing a hydraulic fluid back and forth. Now, if you stop this liquid flowing back and forth, the damper locks the bearing. You can now change the damping properties. This can be done, for example, by changing the flow resistance of the throttle. Another possibility is to change the viscosity of the hydraulic fluid, for example in an electrorheological oil.

Preferably, the soft storage has a position tracking. This can hold the position of the roller despite increasing mass of the winding roll, so that a simple transition to the rigid state of the bearing is possible. The position tracking can also be used to maintain the correct bias of the suspension spring according to the mass of the winding roll, so that no lowering or lifting of the roller takes place during the transition from stiff to soft.

Preferably, the system natural frequency changing device has a vibration sensor. The vibration sensor determines whether a vibration occurs and, if so, how big it is. If a vibration occurs or the vibration exceeds a predetermined amplitude, then the system natural frequency varying means may be actuated to change the system natural frequency.

In an alternative or in addition it can be provided that the system natural frequency changing means comprises a control device in which a relationship between roll diameters and switching states is stored. In many cases, based on empirical values, one will know which states, ie which roll diameter and at which speed, set critical states. Now you can make the switching of the system's own frequency on reaching a corresponding time in the winding process.

Preferably, the roller bearing has a bearing which is supported by a hydraulic cylinder, wherein the hydraulic cylinder is in communication with a pressure supply device whose pressure is variable. About the variable pressure can then change the way in which the bearing is supported by the hydraulic cylinder. At high pressure, the rigidity of the bearing is correspondingly high. At a low pressure it is correspondingly lower. This is especially true when in addition a gas volume is connected to the hydraulic fluid.

Preferably, the pressure supply device has a pressure regulating valve. With a pressure control valve, the desired pressure can be easily adjusted.

Preferably, a check valve is arranged between the pressure supply device and the hydraulic cylinder. If the hydraulic cylinder has been moved to a certain position and the check valve is closed, then the hydraulic fluid from the hydraulic cylinder can no longer escape. The bearing is then rigidly mounted, so to speak. If, however, the check valve is opened, then the hydraulic fluid in the hydraulic cylinder can be influenced by the pressure supply device, so that the bearing stiffness is lowered accordingly.

Preferably, the hydraulic cylinder is connected via the check valve with a hydraulic accumulator. The hydraulic accumulator then forms a spring, for example by means of an enclosed gas volume. So if the check valve has opened, then forms the hydraulic cylinder with the hydraulic accumulator, the above-mentioned suspension spring. When the shut-off valve is closed, the hydraulic accumulator is blocked. In this case, the hydraulic cylinder is a rigid connection between the bearing and the foundation or the strangulation.

Preferably, a throttle is arranged between the hydraulic cylinder and the hydraulic accumulator. The throttle removes energy from the reciprocating hydraulic fluid and thus contributes to the damping. If you make the throttle resistance changeable, possibly also from the outside, then it is easy to change the damping.

Preferably, a pressure control device is provided which equalizes the pressures on both sides of the check valve to each other. When switching from hard to soft then it is ensured that the storage position does not change. Overall, this can be a small working range of storage of, for example ± 2 mm guaranteed.

Preferably, the bearing has at least one movement stop. In operation, only relatively small vibrations are allowed. Larger deflections of the bearing can be avoided by the movement stop. A change of the drive shaft can thus be avoided under certain circumstances. Also on a hinged connection of the drive shaft, which allow larger movements, can be dispensed with.

Preferably, the bearing is guided in a direction of movement. This guidance takes place in the direction of low rigidity or free movement.

In a first embodiment it is provided that the bearing is connected by leaf springs to a chair. Leaf springs have a relatively low stiffness perpendicular to their planar extent. In its planar extent, however, results in a high rigidity. Leaf springs are virtually wear-free, especially when the load is swinging.

In an alternative embodiment it can be provided that the bearing is rotatably supported by a lever. A small rotation about the pivot point of the lever is allowed. A lever additionally allows moving apart of the rollers in a Doppeltragwalzenwickler, which is favorable, for example, with increasing winding diameter.

Finally, the bearing can be guided linearly. Again, it is possible to change the distance between two support rollers.

To influence the natural frequency of the system, the rigidity of the roller can also be changed. The stiffness can be changed, for example, by increasing its internal pressure or by activating or deactivating internal stiffeners.

It is also possible to change the mass of the roller. This can be realized, for example, by introducing or removing a liquid from the roll.

Fig. 1

eine schematische Darstellung einer Rollenwickeleinrichtung,

Fig. 2

eine schematische Darstellung einer Einrichtung zur Änderung einer Systemeigenfrequenz und

Fig. 3

verschiedene Möglichkeiten für eine Lagerführung.

The invention will be described below with reference to a preferred embodiment in conjunction with the drawings. Herein show:

Fig. 1

a schematic representation of a roll winding device,

Fig. 2

a schematic representation of a device for changing a system eigenfrequency and

Fig. 3

different possibilities for a warehouse management.

A roll winding device 1 according to FIG. 1 is designed as a double take-up roll winder. The roll winding device 1 has two support rollers 2, 3, which form a winding bed 4, in which a winding roller 5 is located. The winding roll has a winding tube 6, on which a paper web 7 is wound. The paper web 7 is unwound from a spool 8, which is rotatably mounted in a development not shown. Only schematically illustrated is a guide roller 9. Depending on the desired web guide, of course, several guide rollers 9 may be present.

Usually, such a reel winding device is also provided with a longitudinal cutting device 10, which divides the paper web 7 into a plurality of mutually parallel partial webs. The partial webs may have a width in the range of about 0.3 to 4.8 m.

A support roller 11, which is also referred to as a rider or load roller, presses the winding roller 5 with a predetermined force in the W i ckelbett 4. The support roller 11 is used at the beginning of a winding operation to the paper web 7 as hard as possible to the winding tube 6 wrap. For this purpose, a higher force is applied. In a later section of the winding process it serves to hold the winding roll 5 in the winding bed 4, so to prevent jumping out.

The two support rollers 2, 3, of which at least one is driven, are mounted in bearings 12, 13. The bearings 12, 13 are shown here only schematically. At least one of the two bearings 12, 13 has a variable rigidity, which will be explained in more detail with reference to FIG. 2.

Fig. 2 shows the bearing 12, which is not supported directly on a foundation 14, such as a hall floor, or in a chair, but via a hydraulic cylinder 15. The hydraulic cylinder 15 has a piston 16 which defines a pressure chamber 17. A biasing spring 18 pushes the piston 16 in a direction in which the pressure chamber 17 is minimized. In the pressure chamber 17, a movement stop 19 is arranged, which limits the movement of the piston 16 and thus the movement of the bearing 12, which is connected to the piston 16 via a rod 20. Also for the other direction of movement of the piston 16 may be provided at a distance of a few millimeters, a movement stop.

The bearing 12 is associated with a position sensor 21, which may also be referred to as a "displacement sensor". The position sensor 21 continuously detects the position of the bearing 12 and therefore is able to detect vibrations that the bearing 12 performs. If the bearing 12 vibrates, then also wears the support roller 2 carried by him.

The pressure chamber 17 is connected to a supply line 22. In the supply line 22, a first pressure sensor 23 is arranged. In a section of the supply line 22, the pressure chamber 17 with a pressure supply device 24, a check valve 25 is arranged, which interrupts a connection between the pressure chamber 17 and the pressure supply device 24 in the blocking position shown in Fig. 2, which is effected by a spring 26. When the check valve opens, for example by means of an electromagnetic drive 27, then a connection between the pressure supply device 24 and the pressure chamber 17 is given.

The pressure supply device 24 has a pressure source 28, for example a pressure connection or a pump, and a pressure regulating valve 29. At the output of the pressure regulating valve 29, a second pressure sensor 30 is arranged.

The supply line 22 is connected on the side facing away from the pressure chamber 17 of the check valve 25 via a throttle 31 with a hydraulic accumulator 32. The hydraulic accumulator acts as a hydraulic spring. It usually has a gas volume or other compressible volume. When the check valve 25, as shown, is closed, results in a high rigidity of the storage. The storage is almost as stiff as in a usual today firm screwed to a chair. Of course, the hydraulic cylinder can also be attached to a chair instead of the foundation 14.

If the check valve 25, however, is opened, then results from the coupled hydraulic accumulator 32 a significantly reduced bearing stiffness. About the size of the hydraulic accumulator 32, the stiffness can be adjusted or adapted. The throttle 31 allows optimized damping of the resulting lower natural frequency.

When the check valve 25 is open, the pressure is controlled with increasing mass of the winding roller 5 so that the position of the bearing 12 remains stationary. In this case, the position sensor 21 located on the bearing 12 is used as the error sensor.

When the check valve 25 is closed, the pressure of the hydraulic accumulator 32 is controlled by means of the second pressure sensor 30 to the pressure in the pressure chamber 17, which is determined by the first pressure sensor 23, adapted. When switching from hard to soft, so when switching the check valve 25, thus ensuring that the position of the bearing 12 does not change.

Overall, a small working range of storage, e.g. ± 2 mm. Larger deflections of the bearing 12 can be safely avoided by attacks, such as the stop 19. This work area refers to the roller as a whole. Of course, the difference in the position of the bearings at both axial ends of the roll must be substantially less, for example less than 0.1 mm, so that the winding roll does not run out of the device.

The bearing 12 is guided. Possible embodiments of the bearing guides are shown in FIG.

Fig. 3a shows a first embodiment, in which the bearing 12 is secured by leaf springs 33 to the frame 34. The bearing 12 is displaced in the direction of a double arrow 35. In the direction of this double arrow 35, the rigidity of the leaf springs 33 is low. Accordingly, a movement is possible. Perpendicular to this results in a high stiffness. The storage with leaf springs 33 is wear-free in particular with a vibrating load.

In Fig. 3b, the bearing 12 is mounted on a lever 36 which is rotatable about a pivot point 37 in the frame 34. A rotational movement about the pivot point 37 of the lever 36 is permitted. Since these are relatively small movements, see the above-mentioned ± 2 mm, the movement of the bearing 12 is almost linear with respect to the stiffening.

Fig. 3c shows a third embodiment, in which the bearing 12 is supported by rollers 38 on the frame 34. Accordingly, the bearing 12 is also movable in the direction of a double arrow 39 relative to the frame 34. It is therefore a linear guide.

The switching between soft and hard storage, so switching the check valve 25, can be done either via a controller or via a control.

A controller can be used when it is known from a winding process, when for which switching state uncritical diameter of the winding roll 5 are present, so that can be switched according to controlled.

If such a relationship can not be detected precisely, because e.g. the uncritical areas for the switching states do not overlap each other over the entire winding process, it can be detected by suitable sensors, such as the position sensor 21, the vibration state and triggered dependent on this switching between the individual storage conditions.

Claims (28)

Roller winding device with at least one roller against which a winding roller abuts during winding, characterized in that a system natural frequency changing device (100) is provided, with which a system natural frequency of a system formed by roller winding device (1) and winding roller (5) can be changed. Roller winding device according to claim 1, characterized in that the system natural frequency can be switched between at least two values. Roller winding device according to claim 1, characterized in that the system own frequency is continuously variable. Roller winding device according to one of claims 1 to 3, characterized in that the system own frequency via a change of the roller (2, 3) or the roller bearing (12, 13) is variable. Roll winding device according to one of claims 1 to 4, characterized in that the winding roller (5) is mounted and the system natural frequency is variable via a change in the bobbin storage. Roll winding device according to claim 4 or 5, characterized in that the rigidity of the roller bearing (12, 13) is variable. Roller winding device according to claim 6, characterized in that the roller (2, 3) is optionally rigid or soft storable. Roll winding device according to claim 7, characterized in that the roller is mounted with a bearing which can be optionally coupled to a foundation (14) or a stirrup or can be mounted on a suspension spring. Roll winding device according to claim 7 or 8, characterized in that the soft bearing with a damper (15, 31) is combined. Roller winding device according to claim 9, characterized in that the damper (15, 31) has a variable damping. Roller winding device according to claim 9 or 10, characterized in that the damper (15, 31) is designed as a locking device. Roller winding device according to one of claims 9 to 11, characterized in that the damper (15, 31) is designed as a hydraulic damper. Roll winding device according to one of claims 7 to 12, characterized in that the soft bearing has a position tracking. Roller winding device according to one of claims 1 to 13, characterized in that the system inherent frequency changing means (100) comprises a vibration sensor (21). Roller winding device according to one of Claims 1 to 14, characterized in that the system natural frequency change device (100) has a control device in which a relationship between roller diameters and switching states is stored. Roller winding device according to one of claims 8 to 15, characterized in that the bearing is supported by a hydraulic cylinder (15), wherein the hydraulic cylinder (15) is in communication with a pressure supply device (24) whose pressure is variable. Roller winding device according to claim 16, characterized in that the pressure supply device (24) has a pressure regulating valve (29). Roller winding device according to claim 16 or 17, characterized in that a check valve (25) is arranged between the pressure supply device (24) and the hydraulic cylinder (15). Roller winding device according to claim 18, characterized in that the hydraulic cylinder (15) via the check valve (25) with a hydraulic accumulator (32) is connected. Roller winding device according to claim 19, characterized in that a throttle (31) is arranged between the hydraulic cylinder (15) and the hydraulic accumulator (32). Roller winding device according to one of claims 18 to 20, characterized in that a pressure control device (23, 30) is provided, which equalizes the pressures on both sides of the check valve (25) to each other. Roller winding device according to one of claims 8 to 21, characterized in that the bearing (12, 13) has at least one movement stop (19). Roller winding device according to one of claims 8 to 22, characterized in that the bearing (12, 13) is guided in a direction of movement. Roller winding device according to one of claims 8 to 23, characterized in that the bearing (12, 13) via leaf springs (33) is connected to a chair (34). Roller winding device according to one of claims 8 to 23, characterized in that the bearing (12, 13) is rotatably mounted via a lever (36). Roller winding device according to one of claims 8 to 23, characterized in that the bearing (12, 13) is linearly guided. Roller winding device according to one of claims 1 to 26, characterized in that the rigidity of the roller (2, 3) is variable. Roller winding device according to one of claims 1 to 27, characterized in that the mass of the roller (2, 3) is variable.

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